Lunar Luxury: Jaquet Droz Grande Seconde Moon

Jaquet Droz expanded its flagship Grande Seconde series last year with the addition of a dual-time model (we review it here); the La Chaux-de-Fonds-based brand follows it up this year by incorporating another new horological complication to the collection’s classical figure-eight design: the Jaquet Droz Grande Seconde Moon.

Whereas the Grande Seconde Dual Time updated the original model by placing a GMT indication inside the large seconds/date display subdial (the lower circle of the dial’s figure eight), the Grande Seconde Moon adds a striking astronomical moon-phase indicator. Requiring adjustment only once every 122 years and 46 days, the specially developed “mechanism 135” for the moon-phase has a carefully studied gear ratio that makes it much more precise than the 59-toothed mechanism in a traditional moon-phase, which accumulates an error of one day in approximately two years, seven months, and 20 days. The upper subdial — whose design varies slightly according to the version — discreetly displays the hours and minutes.

Like the Dual Time, the Grande Seconde Moon will be available with three dials and two case materials. There are two steel-cased models, one with a silvery opaline dial with Roman numerals in the upper subdial, the other with a deep black onyx dial with thin hour indices in the upper subdial; and one model in an 18k rose gold case, graced with an ivory enamel dial and an applied, satin-finish, rose-gold circular ring surrounding the moon-phase aperture. The cases measure 43 mm in diameter.

The moon-phase disk, nestled inside the circular scales for the seconds and the hand-type date indicator, is made of either blued steel (in the silvered and ivory enamel dial versions) or onyx (matching the dial material of the and other steel model), with tiny gold stars and a realistic-looking gold moon that rotates clockwise in faithful tune with the actual moon’s lunar cycles. The double-level structure of the dial aids in legibility, while a corrector positioned in the side of the case at 8 o’clock — operated by a stylus that is included with each watch — makes adjustments of the moon-phase easy.

All versions of the Jaquet Droz Grande Seconde Moon are on leather straps, and equipped with self-winding mechanical movements. Prices are $15,200 for the steel model with silvery opaline dial, $17,300 for the steel model with black onyx dial (a Jaquet Droz boutique exclusive), and $28,900 for the rose-gold watch with ivory enamel dial.